If a vet is possible, I would take her in. Is she wheezing, coughing, shaking her head, or having an rattles when she breathes? She looks very pale and looks like she is gasping or open-mouth breathing. It could be a fungal infection such as aspergillosis, but viruses or bacterial infections could be possible. Certain worms (capillary worms, gapeworms) can also affect the throat and breathing. If ther vet is not possible, I would go to your feed store and get a wormer--fenbendazole (SafeGuard Liquid Goat Wormer or the Equine Paste) and give her 1.25 ml every day for 5 days. I would also get Tylan 50 injectable, plus syringes and 20 gauge needles, and give her 1 ml twice a day for 5 days, but give it orally. You can give it in injections if you feel comfortable, but it can cause tissue damage at the site. Mycoplasma (MG,) coryza, ILT, infectious bronchitis, and aspergillosis are some common respiratory diseases in chickens.